Accounting for, Mitigating, and Choice of Margins for Moving Tumors.

Tumor motion can lead to uncertainties in delivered dose to patients and undesirable outcomes. Motion management has become an integrated component of the standard of care for moving tumors in external beam radiotherapy with the development of novel imaging and treatment techniques in the past 2 decades. This article reviews the use of advanced and functional imaging to guide target delineation, considerations for margin selections, technique for accounting for and mitigation of tumor motion in treatment planning and delivery, and motion management in radiation therapy.